Effect of aerobic capacity and hearts ability after two years swimming training in adolescent athletes

Introduction

Swimming is a periodical exercise that mostly uses aerobic training and improves the aerobic metabolic ability. The purpose of this study is to investigate the effects on anaerobic threshold, maximal aerobic power (VO2max) and heart’s ability of adolescent athletes after two years swimming training, the changeable extent through training as well as the relationship between the increase of aerobic capacity and the change of heart’s ability.

Methods

Fifteen swimmers were recruited for the investigation comprising of 8 male and 7 female. The average age, height, weight and body surface area of the male and female athletes respectively are 18.38±0.9 and 18.00±1.3yrs; 175.4±4.3 and 166.4±4.2cm; 67.4±2.9 and 58.0±4.9kg; 1.77±0.04 and 1.60±0.08 m2. Training experience 5.6±1.7yrs. Initially all subjects underwent an incremental exercise test on a cycle ergometer. Pulmonary gas exchange was measured averaged over 30-sec periods, using cardiopulmonary exercise system (MAX-I, USA). The heart’s ability parameters were measured using an echocardiography (ALOKASSD-720, Japan). B-type images of lying subjects were measured, but M-type images were displayed and measured.

Results

1.After two years swimming training, the VO2max (l/min) and VO2max (ml/kg• min) were increased by 11.7%, 2.6% for men and by 12.5%, 9.3% for women, respectively. 2.The AT-VO2(l/min), AT-VO2(ml/kg• min) and AT-%VO2 were significantly increased by 58.2%, 45.5%, 35.4%(men) and by 33.8%, 33.8%, 23.1%(women), respectively (P<0.05-0.01). 3.Stroke Volume (SV) of athletes was significantly elevated by 41.4% (men), 33.7%(women), respectively (P<0.01), and Cardiac Output (CO) was increased by 32.0%(men), 35.3%(women), respectively. EF%, △D%, mvcf which reflect myocardial contractility were elevated, but there were all no significant differences. 4. Despite the parameters that reflect early-diastolic filling volume (R, mRFV, R/PWE and PWE) were increased, there were no significant differences.

Discussion/ Conclusions

The purpose of this study is to examine effects of systematic training on anaerobic threshold (AT), maximal oxygen uptake (VO2max), and the systolic and diastolic function of left ventricle, and to find out the relationship between the changes in cardiac function and AT during training. The result of the study showed that both VO2max (1/min) and VO2mae (ml/min. kg) didn’t change evidently after 2 years swimming systematic training , but AT and systolic function markedly increased. And the correlation between cardiac output (CO) and AT was significant (R=0.85) more than between CO and VO2max(R=0.65). The result suggested that there is a relationship between AT and cardiac function. Cardiac function is likely an important reason for effecting of AT. Training can improve diastolic function of left ventricle. This is another suite for heart.

References

[1]. Li Kaigang, et, al. (2003). J Sport science 5, 102-104.
[2]. Ogita F, Hara M, Tabata I. (1996).J. Acta physiol Scand, 4, 435-441.
[3]. Pu Junzong. (1993). Chinese Journal of sport medicine, 2, 91-95.